You never know how people are going to react to technology. Take the telephone. Back in the 19th century, the idea of someone’s faceless voice coming over a wire struck some people as magic and others as deviltry.

Here in the 21st century, the idea that faceless people are making decisions for you and about you without your firsthand knowledge can seem to some as magic and others as deviltry. Like any technology, it’s all in how you use it.

There’s no question that big data has some pitfalls. As has frequently been noted, most recently in a Toronto Globe & Mail story last week, exhibiting too much knowledge about a customer can be perceived as “creepy.” Also frequently noted, most recently in a Wall Street Journal column last week about the various wonders of big data, including Pandora’s music-suggesting prowess: with great power comes great responsibility.

I’m happy to report that some people are applying that latter maxim to the betterment of society’s health and safety.

TechCrunch reported last week on a startup named Breezometer that is compiling air pollution data to give people a sense of what the air quality is like in their neighborhood. It takes freely available pollution data gathered by government agencies and aggregates it with location information and displays it in an app. As someone with occasionally troubled lungs, I love this idea.

At Re/Code last week, the co-chairs of the Future of Privacy Forum cited examples of how government agencies were using big data “in the fight against discrimination and hate” by looking at everything from housing, minority health care, school suspensions, and police behavior.

On an equally serious note, Daniel Heimpel, publisher of The Chronicle Of Social Change, wrote recently on the topic of preventive analytics and child protection. In a detailed and insightful article, he talked about a new paradigm emerging “where big data can be crunched in a way that helps determine which children are at greater risk of being abused,” based on family history, education, economic level, and other factors. As one source noted, “[T]his information can be used for a range of activities – as a ‘check’ for clinical decision-making, to assign more experienced workers to more serious cases, to prioritize families for limited services slots, or to take some other action.”

I’m less happy to report that, on the other side of the spectrum, some people are using big data to engender feelings ranging from bother to bitterness.

Writing at The Week, Ryan Cooper skewers the use of big data in politics, positing that highly targeted political messages managed to turn off the very Democratic voters they were trying to persuade, giving Republicans more power in Washington, D.C. than they’ve had since Herbert Hoover was elected (man, that’s scary).

Cooper notes that “as Democrats, they were hounded incessantly by the infamous Democratic email machine, which piteously howled for money lest liberals, minorities, and the poor be fed immediately into the wood chipper. Almost none of these emails highlighted the positive things that could be accomplished with a vote.”

He also uses a charming story posted last year on the Squarely Rooted blog to support the notion that “data-supported techniques that surely work well in isolation” become “deeply irritating” when everybody starts using them.

But what I really take offense with is venture capitalist Alex Banayan suggestion on Huffington Post last week that big data can make you happier. He talks about the ability of digital assistants to coalesce lots of information in our smartphones and elsewhere in the universe, and thus free us from minutiae. “As we offload our basic tasks to our digital assistants, freeing our crowded minds and letting us focus more on things we love – we will be led to a new era of insight, efficiency, and ultimately, happiness.”

He cites the example of smart apps, keying on an appointment, telling us when to leave the house, how to hire a driver to chauffeur us, and reminding us “to pick up a hat at the store on 7th on our way to the venue.” A hat? A hat? I’ve been dressing myself for a long time, and I don’t need an app to tell me when to buy apparel. That’s just going too far.

It remains to be seen whether we will use our big data powers for good or evil – or both.